Unicode C

Call a JavaScript Function Returning a Boolean

See more JavaScript Examples

Demonstrates how to call a JavaScript function that returns a boolean. Unicode C

#include <C_CkStringBuilderW.h>
#include <C_CkJsW.h>
#include <C_CkJsonObjectW.h>

void ChilkatSample(void)
    {
    BOOL success;
    HCkStringBuilderW sbScript;
    HCkJsW js;
    HCkJsonObjectW result;
    HCkJsonObjectW funcCall;
    BOOL retval;

    success = FALSE;

    // This is the JavaScript function we'll call:

    // function isEven(number) {
    //     return number % 2 === 0;
    // }

    sbScript = CkStringBuilderW_Create();
    CkStringBuilderW_Append(sbScript,L"function isEven(number) { return number % 2 === 0; }");

    js = CkJsW_Create();

    result = CkJsonObjectW_Create();
    CkJsonObjectW_putEmitCompact(result,FALSE);

    // Call Eval to add the function to the context's global object
    success = CkJsW_Eval(js,sbScript,result);
    if (success == FALSE) {
        // Examine the result for an exception.
        wprintf(L"%s\n",CkJsonObjectW_emit(result));

        // Also examine the LastErrorText.
        wprintf(L"%s\n",CkJsW_lastErrorText(js));
        CkStringBuilderW_Dispose(sbScript);
        CkJsW_Dispose(js);
        CkJsonObjectW_Dispose(result);
        return;
    }

    // ------------------------------------------------------------------------------
    // Call the function isEven(8)

    funcCall = CkJsonObjectW_Create();

    // Create JSON specifying the function name and arguments

    // {
    //   "name": "isEven",
    //   "args": [ 8 ]
    // }

    CkJsonObjectW_UpdateString(funcCall,L"name",L"isEven");
    CkJsonObjectW_UpdateInt(funcCall,L"args[0]",8);

    success = CkJsW_CallFunction(js,funcCall,result);
    if (success == FALSE) {
        // Examine the result for an exception.
        wprintf(L"%s\n",CkJsonObjectW_emit(result));

        // Also examine the LastErrorText.
        wprintf(L"%s\n",CkJsW_lastErrorText(js));
        CkStringBuilderW_Dispose(sbScript);
        CkJsW_Dispose(js);
        CkJsonObjectW_Dispose(result);
        CkJsonObjectW_Dispose(funcCall);
        return;
    }

    wprintf(L"%s\n",CkJsonObjectW_emit(result));

    // Output:
    // {
    //   "type": "bool",
    //   "value": true
    // }

    retval = CkJsonObjectW_BoolOf(result,L"value");
    wprintf(L"%d\n",retval);

    // Output:
    // TRUE


    CkStringBuilderW_Dispose(sbScript);
    CkJsW_Dispose(js);
    CkJsonObjectW_Dispose(result);
    CkJsonObjectW_Dispose(funcCall);

    }